PI=3.1415926
io.write(" R:")
r=io.read()
--io.write('if you are sure R='  .. r .. '? reply y/n')
function y(r) 
	L=2*r*PI
	S=PI*r^2
		return L,S
end
x,y=y(r)
print('L=' .. x)
print('S=' .. y)


